title: Distal middle cerebral artery aneurysm: A proposition of microsurgical management.
abstract: OBJECTIVE
  Based on a cohort of patients treated on distal middle cerebral artery (MCA) aneurysm by microsurgical approach, the objectives were to assess the following: the postoperative functional outcome, study the causes of early neurological deterioration and to determine the predictive factors of favourable outcome.
  
  
  METHODS
  From a neurovascular prospective database, this retrospective longitudinal study included all the patients treated for cerebral aneurysm located on the distal segment of the MCA over two decades (January 1990-December 2011). The patients were all treated by microsurgical clipping exclusion. Any aneurysm was associated to infectious angiopathy. Data were retrieved from the patient's medical charts. The outcome was analysed twice: during the immediate postoperative period and at 6 months according to the modified Rankin scale. The relative risk was estimated for each variable and the prognostic factors were assessed using a multivariate logistic regression model (P<0.05).
  
  
  RESULTS
  Twenty-eight patients, mean age 40±13.3 years (median: 43 years; range 6-70 years) were divided into the ruptured group (n=20) and unruptured group (n=8). In the ruptured group, the initial clinical status was good (WFNS I-III) in 12 patients (60%) and poor in eight (40%) with an intracerebral haematoma (ICH) in 11 (55%). For both groups, the aneurysm location on the distal MCA decreased at a rate from 64.8% of the insular segment to 25% of the opercular then 10.7% to the cortical. During the hospital stay, neurological deterioration occurred in 16 patients (57.2%). The diagnosed causes were cerebral ischaemia in 10 (35.6%), initial ICH in three (10.7%), hydrocephalus in two (7.1%) and epilepsy in one (7.1%). At 6 months, a favourable outcome (mRS 0-2) was observed in 19 patients (68.1%), a definitive morbidity in seven (24.9%) and death in two (7.2%). Based on the prognostic factors, only the absence of immediate postoperative neurological deterioration was identified as significant for a favourable outcome.
  
  
  CONCLUSIONS
  These rare cerebral aneurysms resulted in a high proportion of poor initial status related to a frequent ICH. Cerebral ischaemia was a major cause of the immediate neurological deterioration and the absence of immediate neurological deterioration was the single identified prognostic factor.
authors.affiliation: Department of neurosurgery, Rouen university hospital, 1, rue de Germont, 76031 Rouen cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Calvacante
authors.forename: S
authors.initials: S
authors.lastname: Derrey
authors.forename: S
authors.initials: S
authors.lastname: Curey
authors.forename: O
authors.initials: O
authors.lastname: Langlois
authors.forename: P
authors.initials: P
authors.lastname: Fréger
authors.forename: E
authors.initials: E
authors.lastname: Gérardin
authors.forename: H
authors.initials: H
authors.lastname: Castel
authors.forename: F
authors.initials: F
authors.lastname: Proust
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000473:pathology / Q000601:surgery; D015901:Angiography, Digital Subtraction; D002545:Brain Ischemia / Q000209:etiology; D002648:Child; D018450:Disease Progression; D004827:Epilepsy / Q000209:etiology; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology; D002532:Intracranial Aneurysm / Q000473:pathology / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D020768:Middle Cerebral Artery; D009422:Nervous System Diseases / Q000209:etiology; D019635:Neurosurgical Procedures / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
keywords: Anévrisme cérébral; Artère cérébrale moyenne distale; Cerebral aneurysm; Distal middle cerebral artery; Image-guided system; Microsurgical clipping; Outcome; Système de neuronavigation; Traitement microchirurgicale; Évolution